Association between participant characteristics and syphilis status in women in the recent cohort (n=1182)
| Variable | Syphilis negative, n=1138 (96.3%) | Syphilis positive, n=44 (3.7%) | Syphilis seroprevalence crude POR (95% CI) | P value | Syphilis seroprevalence adjusted POR (95% CI) | P value |
| Demographics | ||||||
| Age category (years) | <0.001 | 0.011 | ||||
| 16–29 | 84 (7.4) | 1 (2.3) | 0.14 (0.02 to 1.08) | 0.059 | 0.21 (0.03 to 1.63) | 0.136 |
| 30–39 | 325 (28.6) | 3 (6.8) | 0.11 (0.03 to 0.37) | <0.001 | 0.16 (0.05 to 0.56) | 0.004 |
| 40–49 | 414 (36.4) | 14 (31.8) | 0.41 (0.21 to 0.80) | 0.009 | 0.48 (0.24 to 0.97) | 0.042 |
| ≥50 | 315 (27.7) | 26 (59.1) | Ref | Ref | Ref | Ref |
| Black race | 935 (82.2) | 40 (90.9) | 2.17 (0.77 to 6.14) | 0.144 | ||
| Hispanic ethnicity | 96 (8.4) | 1 (2.3) | 0.25 (0.03 to 1.85) | 0.176 | ||
| Single relationship status | 778 (69.2) | 30 (68.2) | 0.96 (0.50 to 1.83) | 0.891 | ||
| Low income (<$12 000/year) | 631 (57.6) | 33 (78.6) | 2.70 (1.28 to 5.69) | 0.009 | 2.09 (0.97 to 4.49) | 0.059 |
| Self-reported history of syphilis | 5 (0.4) | 2 (4.6) | 10.8 (2.03 to 57.2) | 0.005 | ||
| Currently pregnant | 11 (1.0) | 0 (0) | * | * | ||
| Medical comorbidities | ||||||
| HIV infection | 825 (72.5) | 34 (77.3) | 1.29 (0.63 to 2.64) | 0.487 | 1.39 (0.66 to 2.93) | 0.390 |
| Hepatitis C (antibody positive) | 146 (12.9) | 17 (38.6) | 4.27 (2.27 to 8.03) | <0.001 | 2.05 (1.01 to 4.14) | 0.046 |
| Drug and alcohol use | ||||||
| Problem alcohol use (>7 drinks/week) | 203 (17.8) | 16 (36.4) | 2.63 (1.40 to 4.95) | 0.003 | 2.21 (1.12 to 4.37) | 0.023 |
| Active or prior drug use | 786 (69.1) | 38 (86.4) | 2.84 (1.19 to 6.77) | 0.019 | ||
| Active or prior injection drug use | 105 (9.2) | 6 (13.6) | 1.55 (0.64 to 3.76) | 0.329 | ||
| Sexual history | ||||||
| Number of lifetime sex partners | 0.687 | |||||
| >100 | 83 (7.3) | 2 (4.6) | 0.65 (0.15 to 2.84) | 0.569 | ||
| 11–100 | 483 (42.6) | 21 (47.7) | 1.18 (0.64 to 2.18) | 0.603 | ||
| 0–10 | 569 (50.1) | 21 (47.7) | Ref | Ref | ||
| Transactional sex (ever) | 410 (36.0) | 24 (54.6) | 2.13 (1.16 to 3.90) | 0.014 |
Values expressed as n (% of non-missing results); reference levels for variables: age (≥50 years old), race (white, Asian, Native American, Pacific Islander and other), ethnicity (non-Hispanic), relationship status (married/living with a partner), income (US$≥12 000), self-reported history of syphilis (no self-reported history of syphilis), currently pregnant (not pregnant), relationship status (married/living with a partner), income (US$≥12 000); HIV status (HIV negative); hepatitis C (negative), problem alcohol use (≤7 drinks a week); active or historical use of cocaine/crack, heroin, methamphetamines or other non-IDU drugs (no active or historical drug use); number of lifetime sex partners (0–10 lifetime partners); and history of transactional sex (reporting never having sex for drugs, money or shelter); missing data: income (n=45, 3.8%), self-reported history of syphilis (n=1, 0.1%), marital status (n=13, 1.1%), HCV antibody (n=2, 0.2%), alcohol use (n=1, 0.1%) and number of lifetime sex partners (n=3, 0.3%). In the multivariable model for women in the recent WIHS cohorts (2011–2015), there were 1182 women of which data for 1134 were used. Backward selection with an alpha level of removal of 0.2 was used; and the following variables were removed from the model: race, active or historical use of cocaine/crack, heroin, methamphetamines or other non-IDU drugs and lifetime number of sex partners.
*No outcomes for crude model.
IDU, injection drug use; POR, prevalence OR; WIHS, Women’s Interagency HIV Study.